I didn't know that whales can sing 并列题名：I didn't know that whales can sing I didn't know that chimps use tools I didn't know that dinosaurs laid eggs I didn't know what time it was 并列题名：I didn't know that chimps use tools I didn't know that some birds hang upside down i wonder why whales sing You don't know what the kids thinking 并列题名：I didn't know that dinosaurs laid eggs